In the fields of liquid crystal display devices, organic electroluminescence display devices, etc., it is proposed to use plastic substrates in place of conventional glass substrates for progress in making a display lightweight, low-profile and high impact.
Whilst substrates of the above type are required to have a low coefficient of thermal expansion, plastic substrates may pose a problem of causing misalignment when forming, for example, electrodes or color filters, due to thermal shrinkage and expansion, since plastic has a higher coefficient of linear expansion than glass.
Although those of various active matrix driving types are recently used especially in the field of liquid crystal display devices thanks to the excellent display quality compared with passive matrix driving types, the above problem is more significant in the liquid crystal display devices of the active matrix driving types because they are required to have a lower coefficient of thermal expansion than the passive matrix driving types.
Another problem associated with plastic substrates is that the mechanical strength thereof is relatively low.
In light of the above problems, there is proposed the use of an optical resin sheet that is formed by impregnating a pre-cured resin in glass fiber such as glass cloth and forming it into a sheet (Patent documents 1, 2 referred below).
Patent Document 1: Official Gazette of Japanese Patent Application Laid-open No. 2003-50384
Patent Document 2: Official Gazette of Japanese Patent Application Laid-open No. Hei-11-2812